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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.jxpath.ri.compiler;
18  
19  import org.apache.commons.jxpath.ri.EvalContext;
20  import org.apache.commons.jxpath.ri.InfoSetUtil;
21  
22  /**
23   * A compile tree element containing a constant number or string.
24   *
25   * @author Dmitri Plotnikov
26   * @version $Revision: 652845 $ $Date: 2008-05-02 13:46:46 -0400 (Fri, 02 May 2008) $
27   */
28  public class Constant extends Expression {
29  
30      private Object value;
31  
32      /**
33       * Create a new Constant.
34       * @param number constant
35       */
36      public Constant(Number number) {
37          this.value = number;
38      }
39  
40      /**
41       * Create a new Constant.
42       * @param string constant
43       */
44      public Constant(String string) {
45          this.value = string;
46      }
47  
48      public Object compute(EvalContext context) {
49          return value;
50      }
51  
52      public Object computeValue(EvalContext context) {
53          return value;
54      }
55  
56      /**
57       * Returns false
58       * @return false
59       */
60      public boolean isContextDependent() {
61          return false;
62      }
63  
64      /**
65       * Returns false
66       * @return false
67       */
68      public boolean computeContextDependent() {
69          return false;
70      }
71  
72      public String toString() {
73          if (value instanceof Number) {
74              return InfoSetUtil.stringValue(value);
75          }
76          return "'" + value + "'";
77      }
78  }